Apparatus for classifying and otherwise handling articles



J. A. HARRIS Feb. 7, 1967 APPARATUS FOR CLASSIFYING AND OTHERWISE HANDLING ARTICLES 4 Sheets-Sheet 1 Filed March 2, 1964 FIG! Feb. 7, 1967 J. A. HARRIS 3,302,804

APPARATUS FOR CLASSIFYING AND OTHERWISE HANDLING ARTICLES Filed March 2, 1964 4 Sheets-Sheet 2 FIG. 3

J. A. HARRIS APPARATUS FOR CLASSIFYING AND OTHERWISE HANDLING ARTICLES Filed March 2, 1964 4 Sheets-Sheet 3 Feb. 7, 1967 J. A, HARRIS 3,302,804

APPARATUS FOR CLASSIFYING AND OTHERWISE HANDLING ARTICLES Filed March 2, 1964 4 Sheets-$heet 4 EMS! WWW

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United States Patent 3,302 804 APPARATUS FOR CLASSlfiYlNG AND UTHERWKSE HANDLlN G AllllCLEd Joseph Angus Harris, Greenisland, Northern llreland, as-

signor to Short Brothers & Harland Limited, Belfast, Northern Ireland, a company of Northern llreiand Filed Mar. 2, 1964, Ser. No. 348,528 Claims priority, application Great Britain, Mar. 5, 1963, 8,783/63; July 16, 1963, 28,167/63 7 Claims. (Cl. 2ll4-16.4)

The invention is concerned with the provision of automatic apparatus which can be employed either (a) for classifying quantities of articles by sorting a random supply thereof into individual compartments (which expression includes chutes, hoppers and the like) respectively allocated to different classes of article, or (b) for the converse process of collecting and forwarding in series, in predetermined order if required, articles withdrawn from a multiplicity of different compartments. An example of use (a) is found in the sorting of the output of a laundry, where it is required to transfer each article as it arrives at a sorting station to the compartment which is intended to hold all the articles of a given customer. An example of use (b) occurs in an automatic vending establishment in which articles may be taken from any of a number of storage compartments according to a customers selection and collected together for passage in series past a costing clerk before packing and delivery to the customer.

The expression classifying is used herein to mean sorting in a broad sense, e.g. with respect to the kind of article, or denomination, size, colour or quality thereof, or as in postal sorting, with respect to the destination of a mail delivery.

The apparatus provided by the invention comprises a series of vertical stacks of discrete compartments, the stacks being arranged about a central axis with corresponding compartments at uniform height, to form a substantially circular-tiered rack, a turn-table mounted within said rack for rotation about said axis, said turn-table carrying one or more transfer units supported thereon with capability of individual adjustment in elevation to an operating level appropriate to any of the tiers, means for effecting such adjustment in elevation, means for temporarily holding a transfer unit at a selected level, and means for rotating the turn-table to bring each transfer unit into operative relationship with each stack of compartments and also to a position opposite a charging or discharging station, and means for effecting a transfer operation between the transfer unit and a selected compartment.

In the preferred embodiment of the invention which is hereinafter described the rotation of the turn-table is continuous, and transfer operations from and to the transfer unit are performed substantially instantaneously under control of mechanism automatically motivated when the transfer unit occupies an appropriate positional relationship to the compartment to or from which the transfer operation is to be made.

It is contemplated that the operations in use (a) of ejecting articles or piles of articles from the transfer units into the compartments, and in use (b) of ejecting articles or piles of articles from the compartments on to the trans fer units, will be in either case carried out in such a way that the article or the like gravitates from the level of the position from which it is to be ejected to the level of the position at which it will be received. For this purpose a transfer unit preferably comprises two separate vertically spaced carrier members, one of which (termed the delivery carrier member) is used when the direction of transfer is from the transfer unit to the compartment, whilst the other (termed the removal carrier member) is used when the direction of transfer is from a compartment to the transfer unit. Said two carrier members are arranged in fixed vertically spaced relationship upon common supporting means, and suitable mechanical means are provided for raising the dual carrier member assembly to an operation al position relative to any tier of the compartments, the delivery carrier member being somewhat above the level of the tier and the removal carrier member somewhat below that level,

For use (a) the apparatus will comprise means for delivering articles to be classified successively to the charging station and for transferring them to the delivery carrier members of a transfer unit; for use (b) it will comprise means for receiving articles from the removal carrier members of the transfer units at the discharging station and for removing them in sequence therefrom. In either case the mechanism for rotating the turn-table and for adjusting the transfer units in elevation to the appropriate tier or station level will be actuated by the machine attendant through suitable remote control means.

In the case of use (a) it is contemplated that articles to be classified will approach the charging station in succession, as by an endless belt input conveyor, or in piles or groups respectively brought to the charging station on trucks or stillages, that each article will bear or be denoted with a tag or other'visual indication of the class into which it should be sorted (unless the mere visual appear ance of the article renders it unnecessary), and that the attendant controlling the apparatus will be provided with means whereby, on learning the classification of an article reaching him, he may operate signal storage means by which the several elements of the apparatus will be preset to perform the successive operations of placing the article on the delivery carrier member of the transfer unit at the charging station, raising the transfer unit on the rotating turn-table to the appropriate tier level, so that when the loaded delivery carrier member registers with the compartment which should receive the article means on the transfer unit may be operated automatically for removing the article from the delivery carrier member to the compartment, whereafter the transfer unit in the course of the subsequent rotation of the turn-table will return automatically to the charging station level and eventually regain the charging station.

In the case of use (b) the attendant will actuate the operational elements of the apparatus so that the removal carrier member of a transfer unit is brought, by appropriate adjustments in elevation and rotation of the turntable, into receiving relationship with a selected compartment from which an article is to be removed; means will then be operated for discharging the article from the compartment on to the removal carrier member, whereupon the transfer unit will travel round in the course of the rotation of the turntable and then be adjusted in elevation until it is brought into delivery relationship with a chute or the like, when means will be operated automatically for removing the article from the carrier member for transport from the rack to a delivery point.

Where it is required that the apparatus shall be capable of both uses (a) and (b), it may be found convenient to locate the charging station at ground level, which may be at the level of the lowest tier of the rack, and to arrange the discharging station at a convenient height vertically above the charging station, the aforementioned chute or the like being such as to deliver the articles at ground level at a point spaced laterally from the charging station.

The remote control and signal storage mechanisms whereby the attendant predetermines the several mechanical operations required of the components of the apparatus for any particular performance according to uses (a) and (b) as aforesaid, form no part of this invention, but it will be understood that each transfer unit must be provided with its particular means of response to signals received from the control apparatus and of translating them into the required movement giving effect to their intention.

In order that the manner in which the invention may be carried into effect may be more clearly understood there follows a description of certain particular embodiments of the invention, reference being made to the accompanying diagrammatic drawings, in which FIG. 1 is an elevation and FIG. 2 is a plan of the apparatus as a whole. FIG. 3 is a fragmentary perspective view illustrating the positional relationship between a transfer unit and compartments in a rack having two tiers and FIG. 4 is an elevation thereof as viewed substantially tangentially to the periphery of the transfer unit. FIGS. 5 and 6 are fragmentary perspective views respectively illustrating two alternative modes of transfer operation between a transfer unit and a compartment. FIG. 7 is a fragmentary perspective detail of the delivery carrier member of a transfer unit, showing the trap-door mechanism thereof.

Referring to the general illustrations in FIGS. 1 and 2, it will be seen that the apparatus comprises a series of vertical stacks A disposed in circular plan form, each stack A containing a plurality of superposed compartments B, the corresponding compartments in the several stacks being arranged at uniform levels to form a circular-tiered rack. Mounted co-axially within the rack is a rotary turn-table C carrying a plurality of transfer units D. The turntable C consists of upper and lower wheel-like members joined by pairs of vertical guidebars, on which the transfers units D are slidably mounted. Each transfer unit D is capable of being adjusted in elevation between a position, e.g. as shown at the right-hand side of FIG. 1, in which it may receive articles to be classified at the charging station, and a position in which it may discharge such articles into any selected compartment B of any desired stack A. At the left-hand side of FIG. 1, the transfer unit is shown in discharge relationship with the uppermost compartment B of a stack. In this particular instance each transfer unit D possesses only a single carrier member; the compartments may contain radially slidable receptacles which, for collection of the classified articles contained therein, may be Withdrawn manually from outside the rack.

Each transfer unit D is provided with an open-ended shovel-like tray E mounted with capability of sliding movement radially of the rack between a position in which it lies within the unit D, as shown at the righthand side of FIG. 1, to a discharge position in which it extends over the open top of a compartment B, as shown at the left-hand side of FIG. 1. A pneumatic ram or jack F incorporated in each transfer unit, and operated through the medium of a trailing flexible pipe-line indicated at G connected with the attendants control apparatus, is provided for effecting the outward projection of the tray E into the discharge position on arrival at a selected compartment B. The same jack F, or a spring energised by the outward movement of the tray, may be used to impart a sudden retractile movement to the tray so that an article supported thereon will be deposited by gravity into the subjacent compartment B. The tray E is preferably accelerated somewhat just before its outward projection movement is terminated in order that the residual outward momentum thereby imparted thereto may ensure a clean deposit of the article.

FIG. 2 shows a subsidiary conveyor H by which articles to be classified are brought in succession to an attendant seated at J. Unless the classification appropriate to the articles can be recognized from their visual appearance, each article will bear, or be denoted by, a tag by which this information is given to the attendant, whose task it then is to operate suitable remote control and signal storage means for actuating mechanism whereby, after an article has been loaded onto the transfer unit as it rotates past the charging station, the transfer unit is immediately raised to the level of the appropriate tier of compartments, so that when the transfer unit arrives at a position in discharge relationship with the compartment in that tier which should receive the article, the latter will be deposited therein as aforesaid. Thereafter, in the course of the rotation of the turn-table the transfer unit is restored to the level of the charging station to which it will return in readiness for the next charging operation.

The reference letter K indicates a discharging station to which in operation according to use (b) articles or groups of articles withdrawn from a compartment B can be brought by a transfer unit of the preferred kind shown in FIGS. 3 and 4, which will be described later. The turn-table is driven by a motor M geared to a rack as shown.

In a preferred form of the apparatus, shown in FIGS. 3 and 4, the compartments of the rack take the form of bins 10 mounted in cantilever upon a structure 11 so as to project inwardly therefrom in positions radial of the centrally mounted turn-table bearing the transfer units. Such an arrangement enables the transfer operations to be performed by lateral sweeping motions of the transfer units past the bins. The transfer unit incorporates a chassis 12 which is mounted for vertical sliding movement throughout the height of the stacks of bins 10 upon guide-bars 13 supported on the turn-table frame 14. Fixed to said chassis 12 are two carrier members disposed in vertically spaced relationship, viz. the delivery carrier member 15 and the removal carrier member 16, the arrangement being such that as the turn-table rotates, the delivery carrier member 15 sweeps in a plane above the bins of the selected tier and the removal carrier member 16 executes a similar movement beneath the bins of that tier. It will be noted that the removal carrier member 16 takes the form of a high-sided receptacle having a capacity substantially equal to that of a bin.

Mounted on the turn-table in respect of each transfer unit is a jack 141 of which the operating member '142 is connected at its foot to the base of the chassis 1'2. Said jack 141 is capable of raising and lowering the chassis so that the carrier members 15, 16 may be brought to the appropriate level of either tier of bins 10. The jack 141 also serves to hold the transfer unit chassis at the level of a selected tier of bins until such time as the transfer unit completes its rotation around the rack. Associated with the jack 1-41 is a subsidiary jack 143 the function of which is to raise the chassis by the small amount necessary to bring the removal carrier member 16 into close proximity with the underside of a bin 10 on discharge from the latter according to use (b). The jack 141 is energised by the machine attendant immediately after initial loading of the transfer unit delivery carrier member 15, through the medium of suitable remote control mechanism.

In this instance the mode of transfer of an article from the delivery carrier member 15 to a bin 10, and from a bin 10 to the removal carrier member 16, and from the removal carrier member 16 at a discharge station, is by deposit through trap doors provided in the floors of the carrier members and bins. The constructional arrangement of the delivery carrier member of a transfer unit so provided is illustrated in FIG. 7, from which it will be seen that the floor of the receptacle which forms the carrier member consists of two leaves 315, 415 which are mounted on shafts 3151 and 4151, the projecting extremities of which carry bell-crank levers 3152 and 4152, respectively. Said levers 3152, 4152 are coupled together by a rod 3153 so that the shafts 3151 and 4151 are constrained to rotate in contrary directions to the same extent, thereby causing the leaves 315, 415 to close simultaneously, when a bowl 3154 on the bell-crank lever 3152 is tripped by a cam 3155 fixed on the rack frame.

Said leaves 315, 415 are maintained closed and subsequently opened by the mechanisms hereinafter described.

FIG. 5 shows an alternative mode of transfer between the carrier members and the bins, and vice versa, which may be used in the apparatus described with reference to FIGS. 1 and 2, and which may also be used, with such slight modifications as are hereinafter explained, in apparatus in which the carrier members of the transfer units sweep laterally over and beneath the bins in the manner hereinbefore described with reference to FIGS. 3 and 4. The transfer unit shown in FIG. 5 comprises a delivery carrier member 151 and a removal carrier member 161, which are supported by a common chassis 121 mounted for vertical sliding movement on guide-bars 131 forming part of the turn-table structure (not shown). Said carrier members respectively incorporate open-ended shovel-like trays 1511 and 1611 which are adapted for individual horizontal sliding movement radially of the rack; for this purpose each of said trays is connected to a pneumatic jack 1211 which partakes of the vertical movement of the transfer unit, being guided for that purpose by a third guide-rod 132, and provision is made for connecting a suitable flexible trailing duct (not shown) to each jack for supplying pressure thereto.

In operating according to use (a), i.e. for transfer of an article from the delivery carrier member 151 to a bin 10, the ram 1211 of the tray 1511 is energised to project the latter towards the position shown when, in the rotation of the turn-table, it arrives opposite the bin. Momentarily before completing its outward stroke a sudden acceleration is imparted to the tray by the jack whereupon the jack pressure is released and a powerful return spring (not shown), connected to the tray 1511, is effective to withdraw the tray, causing the article carried thereon to be deposited cleanly into the open top of the bin. The numeral 1214 indicates a damper governing the retraction of the tray.

In operating according to use (b), i.e. for transfer of the contents of a bin to the removal carrier member 161, the tray 1611 is advanced by its jack 1211 into the position shown, when rotation of the turn-table brings the transfer unit opposite the bin, though without the accelerated motion imparted to the tray 1511. At this stage, mechanism (not shown but similar to that used to operate the tray 1511) is operated to impart to the hing 10, which is open at its inner end, a sudden retractile movement, whereby its contents are deposited on the tray 1611 which is then returned, e.g. by the jack 1215, and transported by subsequent rotation of the turn-table towards the discharge station.

Where the mode of transfer illustrated in FIG. 5 is used in apparatus in which the transfer units sweep laterally above and beneath bins mounted in cantilever as shown in FIGS. 3 and 4, the clean transfer of an article from the delivery carrier member tray 1511 to a bin and from a bin to the removal carrier member tray .1611, may require that the transfer unit chassis 121 be so constructed that the delivery carrier member tray 1511 leads the removal carrier member tray 1611 in the direction of lateral traverse by a distance equal to that traversed in the time taken to effect the retractile displacement of the tray 1511, or to discharge the bin upon the tray 1611.

Another mode of transfer between the delivery carrier members and the bins, in apparatus in which the former sweep laterally over the latter, as hereinbefore described with reference to FIGS. 3 and 4, is illustrated in FIG. 6. In this case the delivery carrier member .152 is provided with a tray 1521 which is capable of individual sldiing motion on the member 152 in a lateral direction with respect to the bin 10. Mounted upon each end of the bin at 101 is a tripping-gear comprising lever 102 carrying at its upper end a bowl 103 and connected by a rod 104 to one arm of a bell-crank lever the other arm of which carries a bowl 105. Fixed to the end of the delivery carrier member 152, and to the end of the tray 1521, respectively, are two depending lugs 1522 and 1523. A jack 1021 is connected to the lever 102 and, when actuated as hereinafter described, it operates said lever to bring the bowls '103 and respectively into the paths of the lugs 1.522 and 1523. A tension spring 1524 is connected between the leading side of the carrier member 152 and a point on the underside of the tray 1521.

In operation, as the carrier member 152 sweeps over the bin 10 in the direction of the arrow X, the lugs 1523 on the tray 1521 are arrested by impingement against the bowls 105. The carrier member continues its movement whilst the tray is held stationary until the lugs 1522 engage the bowls 103 on the levers 102, causing the latter to rock about their pivots 101 and to rotate the bellcrank levers carrying the bowls 105 until the latter are freed from the lugs 1523. The spring 1524, having been energized by the detention of the tray 1521 relative to the carrier member 152, now imparts a sudden acceleration to the tray to restore it to its initial positional relationship to the carrier member, and the article carried by the tray, being retarded by its inertia, is deposited by gravity into the bin 10.

All the modes of transfer hereinbefore described can advantageously be used for handling articles which are fragile or liable to crushing, or which should be deposited upon the receiving element in an undisturbed fiat condition. It is desirable that the floors of the transfer unit carrier members illustrated in FIGS. 5 and 6 should be inclined away from the direction of movement of said members by which the transfer is effected, to ensure that contact between the floor and the underside of the article is immediately lost.

The several functions of operating the trap-door floor mechanisms provided in the embodiments illustrated in FIGS. 3, 4 and 7, of operating the jack 143 shown in FIG. 4, of projecting and retracting the trays 1511 and 1611 and the bin 10 shown in FIG. 5, and of operating the jack 1021 shown in FIG. 6, are severally governed by the machine attendant through signal storage mechanism of which the signal transmitter unit is shown generally at 30 consisting of a plurality of pivotal fingers, there being provided on each transfer unit a mechanical memory indicated generally at 31 consisting of similar pivotal fingers adapted to co-operate with the unit 30, by which signals fed into said storage mechanism are translated into a particular arrangement of the fingers 31, which then cooperate with fixed stops (not shown) on the machine frame to initiate the requisite mechanical or other movements of the respective components in appropriately timed relationship.

Where, as in the embodiment illustrated in FIG. 2, the articles to be classified are brought to the charging station by a subsidiary conveyor (e.g. the conveyor H), they may be placed by the attendant in turn upon a feeding member such as a shovel-like member mounted with capability of being moved between a position beneath the delivery point of said subsidiary conveyor and a position above that which is occupied by the transfer unit when it arrives at the charging station. Said feed shovel may be moved to the charging position either manually by the attendant or by suitable powered mechanism, and a trap-door arrangement in the floor of the shovel, similar to that hereindescribed with reference to FIG. 7, may be triggered automatically as the transfer unit passes beneath it, to effect the removal of the article to the latter from the feed shovel.

In an apparatus operating according to use (a), the compartments of the rack tiers may accommodate movable containers (such as laundry boxes or bags) which may be removed from the outside of the rack through the open outer ends of the compartments. Alternatively, or additionally, the compartments may each be capable of being tipped inwardly by mechanical or other means actuated by the attendant, so that its contents are dis charged into a transfer unit for operating according to use (b). In another alternative arrangement for use (a) each compartment is arranged to communicate at its outer open end with a chute, a pneumatic conveyor trunk, or the like, by which articles may be despatched as sorted to desired destinations or to other receptacles. Similarly, for use (b), the compartments may be supplied with articles fed through chutes, pneumatic trunks or the like connected to their outer ends.

Arrangements may be made whereby, on the deposit of the last article of a pile which is to be placed in a particular compartment, the operation of the delivery carrier member which effects such last deposit is automatically followed immediately by the triggered deposit of the contents of the compartment upon the subjacent removal carrier member, so that the pile of articles may forthwith be conveyod to the discharging or wrapping station.

It will be understood that any of the mechanical movements of the transfer units, and of the component elements thereof, and of the compartments, instead of being operated pneumatically, may be powered by hydraulic, steam-driven or electric acutators, or by the use of elastic springs.

It is a valuable advantage of the apparatus hereindescribed that it is particularly well adapted for the delivery of classified piles of articles in batches to a wrapping machine at which each batch is individually wrapped in readiness for despatch elsewhere. It is further proposed that a polythene film or other transparent wrapping material should be used, a sheet thereof being fed across the wrapping machine table before the deposit of the article thereon and, after such deposit, being wrapped about the pile of articles and secured along the edges by heat-sealing or other appropriate means. An address label, a laundry list, printed sheet or the like bearing delivery instructions, may be attached to an edge of the wrapper and enclosed around the end of the parcel within the wrapping sheet which, being transparent, permits the list or the like to be read by a delivery van driver whilst ensuring that it does not become separated from the parcel.

What I claim as my invention and desire to secure by Letters Patent is:

1. Apparatus for classifying articles, comprising a plurality of discrete compartments arranged about a central axis in a plurality of vertically spaced tiers to form a substantially circular rack, each of said compartments having a retractile floor and means for substantially instantaneously retracting said floor, charging and discharging stations located at respective points in the circumference of said rack, a turntable mounted within said rack for rotation about said axis, at least one transfer unit carried by said turntable and adjustable thereon in elevation to an operating level appropriate to any one of the tiers of the rack, means for continuously rotating said turntable to bring said transfer unit into operative positional relationship with said charging and discharging stations and with the different compartments of a tier in turn, said transfer unit comprising a delivery carrier member and a removal carrier member in such fixed vertically spaced relationship that when said transfer unit occupies an operational position relative to any tier of the rack, said delivery carrier member is disposed at a level above said tier and said removal carrier member is disposed at a level below said tier, said delivery carrier member having a retractile floor and said transfer unit having means for substantially instantaneously retracting said floor, and selector means adapted to actuate said floorretracting means of said compartments and of said transfer unit selectively.

2. Apparatus according to claim 1, wherein said retractile floors of said compartments and of said delivery carrier member incorporate trap-door means.

3. Apparatus for classifying articles, comprising a plurality of discrete compartments arranged about a central axis in a plurality of vertically spaced tiers to form a substantially circular rack, a rack supporting structure supporting said compartments in cantilever from the outer periphery of said rack, each of said compartments having a floor incorporating trap-door means and means for substantially instantaneously opening said trap-door means, charging and discharging stations located at respective points in the circumference of said rack, a turntable mounted within said rack for rotation about said central axis, at least one transfer unit carried by said turntable and adjustable thereon in elevation to an operating level appropriate to any one of the tiers of said rack, means for continuously rotating said turntable to bring said transfer unit into operative positional relationship with said charging and discharging stations and with different compartments of a tier of said rack in turn, said transfer unit comprising a delivery carrier member and a removal carrier member vertically spaced from one another so that when said transfer unit is in operative relationship with any tier of said rack said delivery carrier member passes directly above the compartments of said tier and said removal carrier member passes directly below the compartments of said tier, said delivery carrier member having a floor incorporating trap-door means and said transfer unit having means for substantially instantaneously opening said trap-door means, and selector means adapted to actuate said trap-door opening means of said compartments and of said transfer unit selectively.

4. Apparatus for classifying articles, comprising a series of vertical stacks of discrete compartments, said stacks being arranged about a central axis with corresponding compartments at uniform height to form a substantially circular tiered rack, the compartments of each stack being mounted in cantilever so as to project inwardly of the rack toward said central axis, a charging station located at a point in the circumference of said rack, a turntable mounted within said rack for rotation about said axis, at least one transfer unit carried by said turntable and adjustable thereon in elevation to an operating level appropriate to any one of the tiers of the rack, means for continuously rotating said turntable to bring said transfer unit into operative positional relationship with said charging station and with corresponding compartments of each stack in turn, said transfer unit having a retractile floor including trap-door means and means being provided for retracting said floor substantially instantaneously, each transfer unit being mounted on the turntable so that, in the rotation of the latter, said trap-door means of said transfer unit passes directly over the compartments in a tier of the rack, and selector means at the charging station adapted to actuate said trap-door means when said transfer unit occupies an appropriate positional relationship with the compartment to which an article is to be supplied, to allow said article to drop freely into said compartment.

5. Apparatus for classifying articles, comprising a series of vertical stacks of discrete compartments, said stacks being arranged about a central axis with corresponding compartments at uniform height to form a substantially circular tiered rack, the compartments of each stack being mounted in cantilever so as to project inwardly of the rack towards said central axis, a charging station located at a point in the circumference of said rack, a turntable mounted within said rack for rotation about said axis, at least one transfer unit carried by said turntable and having a retractile floor, said transfer unit being adjustable on said turntable in elevation to different operating levels at each of which said retractile floor passes directly over the compartments in a different one of the tiers of the rack, means for continuously rotating said turntable to bring said transfer unit into operative positional relationship with said charging station and with corresponding compartments of each stack in turn, means for re-- tracting said retractile floor substantially instantaneously,

and selector means at the charging station adapted to actuate said floor-retracting means when said transfer unit occupies an appropriate positional relationship with the compartment to which an article is to be supplied, to allow said article to drop freely into said compartment.

6. An apparatus according to claim 5, wherein said retractile floor of said transfer unit includes a floor tray relatively slidable on the latter radially of the rack and wherein said means for instantaneously retracting said floor forms means for imparting sliding movement to said tray to accelerate said tray towards said compartment, and means for subsequently effecting abrupt retractile movement of the tray, leaving the article to drop by gravity into said compartment.

7. An apparatus according to claim 5, wherein said retractile floor of said transfer unit includes a floor tray relatively slidable on the latter in a circumferential direction of the rack and wherein said means for instantaneously retracting said floor forms means for imparting sliding movement to said tray to accelerate the latter in a circumferential direction of said rack, and means for subsequently effecting abrupt retractile movement of the tray, leaving the article to drop by gravity into said compartment.

References Cited by the Examiner UNITED STATES PATENTS 744,316 11/1903 Eitle 214-33 X 1,843,282 2/1932 Horn et al 214-26 X 1,925,442 9/1933 Fournier 21416.11 2,589,561 3/1952 MacKechnie et a1 ..21411 2,691,448 10/1954 Lontz 21416.14 3,055,517 9/1962 Kirkland 214 -1611 MARVIN A. CHAMPION, Primary Examiner.

GERALD M. FORLENZA, Examiner. 

1. APPARATUS FOR CLASSIFYING ARTICLES, COMPRISING A PLURALITY OF DISCRETE COMPARTMENTS ARRANGED ABOUT A CENTRAL AXIS IN A PLURALITY OF VERTICALLY SPACED TIERS TO FORM A SUBSTANTIALLY CIRCULAR RACK, EACH OF SAID COMPARTMENTS HAVING A RETRACTILE FLOOR AND MEANS FOR SUBSTANTIALLY INSTANTANEOUSLY RETRACTING SAID FLOOR, CHARGING AND DISCHARGING STATIONS LOCATED AT RESPECTIVE POINTS IN THE CIRCUMFERENCE OF SAID RACK, A TURNTABLE MOUNTED WITHIN SAID RACK FOR ROTATION ABOUT SAID AXIS, AT LEAST ONE TRANSFER UNIT CARRIED BY SAID TURNTABLE AND ADJUSTABLE THEREON IN ELEVATION TO AN OPERATING LEVEL APPROPRIATE TO ANY ONE OF THE TIERS OF THE RACK, MEANS FOR CONTINUOUSLY ROTATING SAID TURNTABLE TO BRING SAID TRANSFER UNIT INTO OPERATIVE POSITIONAL RELATIONSHIP WITH SAID CHARGING AND DISCHARGING STATIONS AND WITH THE DIFFERENT COMPARTMENTS OF A TIER IN TURN, SAID TRANSFER UNIT COMPRISING A DELIVERY CARRIER MEMBER AND A REMOVAL CARRIER MEMBER IN SUCH FIXED VERTICALLY SPACED RELATIONSHIP THAT WHEN SAID TRANSFER UNIT OCCUPIES AN OPERATIONAL POSITION RELATIVE TO ANY TIER OF THE RACK, SAID DELIVERY CARRIER MEMBER IS DISPOSED AT A LEVEL ABOVE SAID TIER AND SAID REMOVAL CARRIER MEMBER IS DISPOSED AT A LEVEL BELOW SAID TIER, SAID DELIVERY CARRIER MEMBER HAVING A RETRACTILE FLOOR AND SAID TRANSFER UNIT HAVING MEANS FOR SUBSTANTIALLY INSTANTANEOUSLY RETRACTING SAID FLOOR, AND SELECTOR MEANS ADAPTED TO ACTUATE SAID FLOORRETRACTING MEANS OF SAID COMPARTMENTS AND OF SAID TRANSFER UNIT SELECTIVELY. 